Data Monitoring Committees (DMC) are increasingly becoming integrated into the methodical procedure of clinical trials, in order to support sponsors in their central role. Whereas monitors and auditors, respectively, give quality assuring recommendations in compliance with GCP, an implemented DMC is able to give sponsors far-reaching recommendations owing to its access to unblinded data. Besides the main intention of enhancing safety during the conduction of clinical trials, the premature termination of clinical trials due to insufficient efficacy of the investigational medicinal product may be a result. Based on the European Guideline EMEA/CHMP/EWP/5872/03 Corr and based on published literature, criteria and crucial aspects for implementing this independent committee are being named If, in the course of a clinical trial, the implemented DMC notices an alteration in the risk-benefit assessment in the context of pharmacovigilance, immediate notification obligations of the Sponsor to the higher federal authorities and to the ethics committees arise.